FIG. 7.

Doxycycline prevents steroid production through the inhibition of amphiregulin processing. Primary mouse granulosa cells were treated with LH or LH plus doxycycline (75 μM). Progesterone levels (A) and amphiregulin levels (B) in the medium were measured by RIA and ELISA, respectively. Levels of amphiregulin and epiregulin mRNA (C) were measured in primary mouse granulosa cells using real-time PCR. Whole follicles isolated from mouse ovaries were stimulated with LH or LH plus doxycycline (250 μM) and progesterone (D) and testosterone (E) levels in the medium were measured by RIA. Female mice were treated with doxycycline in vivo and serum progesterone levels (F, n = 11 for each group) were determined by RIA. Data are represented as fold induction over MOCK or inhibitor alone (DOX). Each bar represents the average ± SEM (n = 3). Identical results were seen in two experiments. *P < 0.05 relative to MOCK or DOX alone; **P < 0.05 relative to LH/hCG using Student two-tailed t-test.